4-Channel, 625 kSPS, 12-Bit Parallel ADC with a Sequencer AD7934-6 FEATURES FUNCTIONAL BLOCK DIAGRAM V AGND Throughput rate: 625 kSPS DD Specified for V of 2.7 V to 5.25 V DD AD7934-6 V / REFIN Power consumption V REFOUT 2.5V 3.6 mW maximum at 625 kSPS with 3 V supplies VREF 7.5 mW maximum at 625 kSPS with 5 V supplies V 0 IN CLKIN 12-BIT 4 analog input channels with a sequencer SAR ADC I/P CONVST T/H AND MUX Software-configurable analog inputs CONTROL BUSY V 3 4-channel single-ended inputs IN 2-channel fully differential inputs 2-channel pseudo differential inputs SEQUENCER Accurate on-chip 2.5 V reference 0.2% maximum 25C, 25 ppm/C maximum PARALLEL INTERFACE/CONTROL REGISTER V DRIVE 70 dB SINAD at 50 kHz input frequency No pipeline delays High speed parallel interfaceword/byte modes Full shutdown mode: 2 A maximum DB0 DB11 CS RD WR W/B DGND 28-lead TSSOP package Figure. 1 GENERAL DESCRIPTION features flexible power management options. An on-chip control The AD7934-6 is a 12-bit, high speed, low power, successive register allows the user to set up different operating conditions, approximation (SAR) analog-to-digital converter (ADC). The including analog input range and configuration, output coding, part operates from a single 2.7 V to 5.25 V power supply and power management, and channel sequencing. features throughput rates up to 625 kSPS. The part contains a low noise, wide bandwidth, differential track-and-hold PRODUCT HIGHLIGHTS amplifier that handles input frequencies up to 50 MHz. 1. High throughput with low power consumption. The AD7934-6 features four analog input channels with a channel 2. Four analog inputs with a channel sequencer. sequencer that allows a preprogrammed selection of channels to 3. Accurate on-chip 2.5 V reference. be converted sequentially. This part can accept either single- 4. Single-ended, pseudo differential, or fully differential ended, fully differential, or pseudo differential analog inputs. analog inputs that are software selectable. 5. No pipeline delay. Data acquisition and conversion are controlled by standard control 6. Accurate control of the sampling instant via a CONVST inputs that allow for easy interfacing to microprocessors and input and once-off conversion control. CONVST DSPs. The input signal is sampled on the falling edge of , which is also the point where the conversion is initiated. Table 1. Related Devices The AD7934-6 has an accurate on-chip 2.5 V reference that Similar Device No. of Bits No. of Channels Speed can be used as the reference source for the analog-to-digital AD7938/AD793912/10 8 1.5 MSPS conversion. Alternatively, this pin can be overdriven to provide AD7933/AD793410/12 4 1.5 MSPS an external reference. AD7938-6 12 8 625 kSPS The AD7934-6 uses advanced design techniques to achieve very low power dissipation at high throughput rates. The part also Rev. B Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No Tel: 781.329.4700 www.analog.com license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Fax: 781.461.3113 20052007 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. 04752-001AD7934-6 TABLE OF CONTENTS Features .............................................................................................. 1 ADC Transfer Function............................................................. 15 Functional Block Diagram .............................................................. 1 Typical Connection Diagram ................................................... 16 General Description ......................................................................... 1 Analog Input Structure.............................................................. 16 Product Highlights ........................................................................... 1 Analog Input Configurations ................................................... 17 Revision History ............................................................................... 2 Analog Input Selection .............................................................. 19 Specifications..................................................................................... 3 Reference ..................................................................................... 20 Timing Specifications .................................................................. 5 Parallel Interface......................................................................... 21 Absolute Maximum Ratings............................................................ 6 Power Modes of Operation ....................................................... 24 ESD Caution.................................................................................. 6 Power vs. Throughput Rate....................................................... 25 Pin Configuration and Function Descriptions............................. 7 Microprocessor Interfacing....................................................... 25 Typical Performance Characteristics ............................................. 9 Application Hints ........................................................................... 27 Terminology .................................................................................... 11 Grounding and Layout .............................................................. 27 Control Register.............................................................................. 13 Evaluating the AD7934-6 Performance .................................. 27 Sequencer Operation ................................................................. 14 Outline Dimensions....................................................................... 28 Circuit Information........................................................................ 15 Ordering Guide .......................................................................... 28 Converter Operation.................................................................. 15 REVISION HISTORY 2/07Rev. A to Rev. B Updated Format..................................................................Universal Changes to Figure 13...................................................................... 10 Changes to Sequencer Operation Section................................... 14 Changes to Figure 34...................................................................... 21 10/05Rev. 0 to Rev. A Changes to Product Highlights....................................................... 1 Inserted Table 1................................................................................. 1 Changes to Specifications................................................................ 3 Changes to Timing Specifications.................................................. 5 Changes to Pin Function Descriptions.......................................... 7 Added Writing to the Control Register to Program the Sequencer Section.................................................... 14 Changes to the Analog Inputs Section......................................... 17 Changes to the Grounding and Layout Section ......................... 27 1/05Revision 0: Initial Version Rev. B Page 2 of 28